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A Modified Delphi Approach to a New Card Sorting Methodology

Celeste Lyn Paul

Journal of Usability Studies, Volume 4, Issue 1, November 2008, pp. 7-30

Article Contents


Delphi in user-centered design techniques

There are a number of methods currently employed in the practice of user-centered design that have been influenced by or are fundamentally similar to the Delphi technique. Although not strictly limited to user-centered design, the Delphi method of interviewing (Boucher et al., 1972) is a protocol designed to gather information from multiple experts while limiting the influence or bias of any one expert. For example, when researching user groups of a product, an iterative interviewing model would involve members of the client company who are involved in the development of a product (see Figure 2). A participant is asked to create a list of who he or she thinks are users of the product. Once the participant provides his or her answer, he or she is provided with the combined list of the previous participants answers. The participant is then allowed to modify his or her answer based on this new information. What usually results from this review is one of three things: the participant included a user group that was not previously listed, the participant did not consider a user group from the combined list that he or she thinks is valid, or the participant will notice a combination of groups that include the same information. The participant's results are combined with the current list by the moderator for use with the next participant. This interviewing process is continued until a consensus has been reached or obvious patterns of conflict and agreement have been identified.

Figure 2. Iterative moderating model

Figure 2. Iterative moderating model

Iterative interface design is a development strategy used in user-centered design. This strategy often includes frequent usability testing sessions with a small number of participants over the development of a product (Krug, 2000). A linear version of the Delphi moderating model can be incorporated into the testing protocol as a method for gathering feedback and insight (see Figure 3). Participants are given the prototype design to work with and are asked to provide feedback. They are then presented with alternate design ideas that have been created based on feedback from previous participants and allowed to provide additional feedback, particularly if one design is better than another. Because the goals of the testing sessions are to gather design feedback, and not to validate the prototype design, this method is valuable for trying out design ideas developed during the study.

Figure 3. Linear moderating model

Figure 3. Linear moderating model

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